Hello, I am currently working on a small project and I have come across a problem I have not been able to solve myself. My setup is as following, I have a TP-LINK WDR4300 (so ar71xx) router that will be used as an access point to share a WAN connection. The WAN connection is a different wifi. My idea is to use the two on-board wifis as AP (I want both 2.4 GHz and 5Ghz), and then use a USB wifi dongle for the WAN connection. I run OpenWRT and the most recent kernel available (3.14.12). The problems were also present on 3.10 kernels. When configuring this setup, two problems occur: 1) I have tested with several different USB wifi dongles, some using Realtek chipset (rl8192cu driver) and others using Atheros chipset (ath9k_htc driver). The WDR4300 on-board wifi is also Atheros (ath9k driver), and when I use a device from a different "family" (i.e., the Realtek-dongles), the wifi authentication always times out. If I disable the on-board wifi, the Realtek dongle works as expected (connection to WAN wifi can be established). Is there a known problem mixing different Wifi drivers on the ar71xx-platform/WDR4300, or am I doing something wrong? 2) When disconnecting any WIFI dongle, I always get a kernel oops. This happens irrespective of if the dongle is active (for example connected to network) or if I have just connected it to the router. The kernel oops looks like the following (the crash happens at the same place independent of device): [ 429.730000] usb 1-1.1.5.4: USB disconnect, device number 10 [ 429.760000] CPU 0 Unable to handle kernel paging request at virtual address 00100104, epc == 86e93018, ra == 86e93010 [ 429.770000] Oops[#1]: [ 429.770000] CPU: 0 PID: 292 Comm: khubd Not tainted 3.14.12 #4 [ 429.770000] task: 878ad770 ti: 87b0c000 task.ti: 87b0c000 [ 429.770000] $ 0 : 00000000 00000000 00200200 00100100 [ 429.770000] $ 4 : 87b0dce0 87b0dee0 80350000 00000008 [ 429.770000] $ 8 : 00090040 86a6a080 00000020 00090040 [ 429.770000] $12 : 00000013 0000000e 00000007 00000001 [ 429.770000] $16 : 85cc91a0 87b0dcd8 00100100 85cc91a8 [ 429.770000] $20 : 85cc91a0 00200200 86948000 87b41838 [ 429.770000] $24 : 80327df0 8010fe04 [ 429.770000] $28 : 87b0c000 87b0dcc8 00000000 86e93010 [ 429.770000] Hi : 00000350 [ 429.770000] Lo : 00000006 [ 429.770000] epc : 86e93018 ieee80211_remove_interfaces+0x128/0x1b4 [mac80211] [ 429.770000] Not tainted [ 429.770000] ra : 86e93010 ieee80211_remove_interfaces+0x120/0x1b4 [mac80211] [ 429.770000] Status: 1100dc03 KERNEL EXL IE [ 429.770000] Cause : 0080000c [ 429.770000] BadVA : 00100104 [ 429.770000] PrId : 0001974c (MIPS 74Kc) [ 429.770000] Modules linked in: ath9k rtl8192se rtl8192de rtl8192cu rtl8192ce ath9k_htc ath9k_common rtl_usb rtl_pci pppoe ppp_async option iptable_nat ath9k_hw ath usb_wwan smsc95xx rtlwifi rtl8187 rt73usb rt2x00usb rt2x00lib rndis_host qmi_wwan pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv4 mac80211 ipt_MASQUERADE huawei_cdc_ncm cfg80211 cdc_ncm cdc_ether ax88179_178a asix xt_time xt_tcpudp xt_tcpmss xt_string xt_statistic xt_state xt_recent xt_quota xt_pkttype xt_owner xt_nfacct xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_id xt_hl xt_helper xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_addrtype xt_TCPMSS xt_REDIRECT xt_NFQUEUE xt_LOG xt_HL xt_DSCP xt_CT xt_CLASSIFY usbserial usbnet ts_kmp ts_fsm ts_bm slhc rtl8192c_common nfnetlink_queue nfnetlink_acct nf_nat_irc nf_nat_ftp nf_nat nf_defrag_ipv4 nf_conntrack_irc nf_conntrack_ftp iptable_raw iptable_mangle iptable_filter ipt_REJECT ipt_ECN ipheth ip_tables crc16 crc_itu_t crc_ccitt compat cdc_wdm cdc_acm act_connmark act_skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ingress ledtrig_usbdev ip6t_REJECT ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables nf_conntrack_ipv6 nf_defrag_ipv6 ifb ipv6 eeprom_93cx6 arc4 crypto_blkcipher ehci_platform ehci_hcd gpio_button_hotplug usbcore nls_base usb_common mii [ 429.770000] Process khubd (pid: 292, threadinfo=87b0c000, task=878ad770, tls=00000000) [ 429.770000] Stack : 85cc93a0 86f69350 00000000 00000000 87b0dcd8 87b0dcd8 00100100 00200200 [ 429.770000] 86948000 85cc8ae0 85cc9460 86b9fa20 86f69350 00000000 00000000 86e80fac [ 429.770000] 00000004 85cc8ae0 85cc9460 86b9fa20 85cc8ae0 86e14ddc 87b0dd1c 87b0bbd0 [ 429.770000] 86b9fa20 86948000 86b9fa20 86948000 86b9fa00 87b2c580 879ff000 800def9c [ 429.770000] 87b39180 80131108 86b9fa20 86f69350 87b39180 879ff000 86b9fa00 8008d734 [ 429.770000] ... [ 429.770000] Call Trace: [ 429.770000] [<86e93018>] ieee80211_remove_interfaces+0x128/0x1b4 [mac80211] [ 429.770000] [<86e80fac>] ieee80211_unregister_hw+0x3c/0xe4 [mac80211] [ 429.770000] [<86e14ddc>] rtl_usb_disconnect+0x4c/0xf4 [rtl_usb] [ 429.770000] [<87b2c580>] usb_deregister+0x228/0x2ec [usbcore] [ 429.770000] [<8008d734>] __device_release_driver+0x6c/0xd0 [ 429.770000] [<80117f64>] device_release_driver+0x28/0x40 [ 429.770000] [<800edffc>] bus_remove_device+0xec/0x120 [ 429.770000] [<801176fc>] device_del+0x110/0x170 [ 429.770000] [<87b2ad58>] usb_disable_device+0xb0/0x1d8 [usbcore] [ 429.770000] [<87b22920>] usb_disconnect+0xac/0x408 [usbcore] [ 429.770000] [<87b24a68>] usb_reset_device+0xd28/0x15c8 [usbcore] [ 429.770000] [<80121c0c>] do_exit+0x72c/0x744 [ 429.770000] [ 429.770000] [ 429.770000] Code: 27a40018 8fa2001c 8fa30018 <ac620004> ac430000 8fb00010 3c030010 3c020020 24630100 [ 430.110000] ---[ end trace 6ca2573cb8fc44d5 ]--- Has anyone else experienced this or have an idea of how to fix it? My knowledge of wifi in general and the wireless stack in Linux is very limited, so I am not quite sure where to start. When testing the same setup on a router based on a different SoC (WRT1900AC, Marvell Armada XP/370) I do not see any of these problems. Disconnecting wifi dongles works as expected, while any dongle can be used together with the on-board wifi. The same applies to my laptop (running kernel 3.16). Thanks in advance for any help, Kristian -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
